红土镍矿基材料吸附及有氧降解水体污染物

以红土镍矿为研究对象，考察了原矿（HT）及改性矿（HT-FeNi）去除水体中罗丹明B （RhB）的效果.借助XRD、BET、IR等表征手段，结合吸附动力学和等温吸附模拟研究了HT吸附RhB的过程及机制.结果表明：HT的孔隙结构较为丰富，有良好的RhB吸附性能.当HT添加量为0.2g/L时，RhB去除率为39.03%，吸附量达到93.80mg/g.HT添加量增加，RhB去除效果增强，平衡吸附量减小.HT吸附RhB的过程更符合准二级动力学，包含表面扩散及颗粒内扩散两个步骤.等温吸附模型拟合发现Freundlich能够准确描述HT吸附RhB的过程.1/n<0.5，表明吸附过程较易进行.HT经5次循环实验后，吸附量仍能达到39.67mg/g，表明HT有较好的循环使用性能.HT吸附RhB主要归因于Si-O吸附位点.通过气基还原制备得到改性矿（HT-FeNi）.采用SEM、XRD、BET、XPS等手段对HT-FeNi进行表征分析，并考察了HT-FeNi降解RhB的效果.结果表明：HT-FeNi比表面积小（14.374m²/g），主要成分为铁镍双金属.HT-FeNi不能通过吸附作用去除RhB，而HT-FeNi/Air/pH=3体系在40min内RhB降解效率为94%.捕获活性氧物种的实验证明，HT-FeNi/Air/pH=3体系去除RhB过程中起主要作用的活性氧物种是羟基自由基（·OH）.在酸性条件下，HT-FeNi通过活化O₂生成·OH，Ni⁰诱导的Fe²⁺/Fe³⁺循环促使HT-FeNi/Air/pH=3体系生成更多的·OH.将HT-FeNi/Air/pH=3体系应用于去除水体中甲基橙（MO）和二硝基氯苯（DNCB），去除效率分别为47%、78%.

Adsorption and aerobic degradation of water pollutants by laterite nickel ore-based materials

Taking laterite nickel ore as the research object, the removal efficiencies of rhodamine B(RhB) with the raw ore (HT) and the modified ore (HT-FeNi) were investigated systematically. The adsorption mechanism of RhB was studied by X-ray diffraction, specific surface area analyser, infrared spectrum, and the kinetic and isothermal adsorption characteristic analyses. The results show that the HT possesses a relatively rich pore structure and a good adsorption performance on RhB. When added 0.2g/Lof HT, a RhB removal efficiency of 39.03% and a adsorption capacity of 93.80mg/g were reached. The RhB removal efficiency was enhanced, while the equilibrium adsorption capacity was decreased with the increasing dosage of HT. The adsorption kinetics and isotherms of RhB were well fitted by pseudo-second-order kinetic and Freundlich equation, respectively. The adsorption process might include two steps:surface diffusion and intra-particle diffusion. The 1/n was less than 0.5, which indicated that the adsorption process occurred more easily. The adsorption capacity of 39.67mg/g was still remained after 5cycles of experiments, indicating a good recycling performance of HT. The adsorption of RhB by HT was mainly attributed to the adsorption site of Si-O. The modified ore (HT-FeNi) was prepared by gas reduction of raw ore (HT). SEM、XRD、BET and XPS were used to characterize HT-FeNi and the degradation efficiency of RhB with this material was investigated. The specific surface area of HT-FeNi was smaller (14.374m²/g), and its main component was Fe-Ni bimetallic. HT-FeNi could not remove RhB by adsorption. However, the degradation efficiency of RhB could reach 94% in HT-FeNi/Air/pH=3system within 40min. The reactive oxygen species capture experiments indicated that the hydroxyl radical (·OH) played a major role for the RhB degradation. HT-FeNi could activate O₂ under acidic condition and ·OH formed. The Fe²⁺/Fe³⁺ cycle induced by Ni⁰ promoted the production of ·OH. Then HT-FeNi/Air/pH=3system was applied to the removal of MO and DNCB, the removal efficiencies were 47% and 78%, respectively.